ianpac A month ago Solus refused to boot. Grub loaded fine but it then came up with the error the boot kernel 5.15.43-215 was not found. Error you need to load the kernal first. Same error if I choose the previous kernel. I was unable to fix this so just reinstalled Solus as I had no private files stored on this particular SSD. Everything was back to normal but now the same error is back. This time I hope to learn how fix it.
@ianpac As I noted earlier, I do not have the knowledge to do much to help**, but I might be able to point you in a direction.
If I understand correctly:
(1) You installed Solus and it worked fine for a while. At some point, Solus stopped booting and you got this error: "error: file '/boot/com.solus-project.current ...' not found".
(2) You then reinstalled. Again Solus worked fine for a while, but at some point, Solus stopped booting and you got the same error.
If my understanding is correct, it looks like something -- perhaps an update, maybe a change to Grub -- modified/replaced a configuration file so that the location the boot loader searched to find the kernel (com.solus-project.current ...) changed from /boot/EFI to /boot. If you can figure out what file was changed, and what changed the file, you will be well on the way to understanding the problem.
A possible second direction: When you installed, did you use the "wipe everything off this drive and repartition" method? If not, perhaps you are dealing with artifact installations on the drive. I am really puzzled about how Grub showed up in an EFI installation of Solus.
** My Solus setup is entirely different from yours. I am using EFI installation, I do not have Grub, and my kernel/initrd files are in /usr/lib64/kernel, not in root or /boot or /boot/EFI. So I am unable to replicate or test anything remotely similar to your setup. I do have a similar setup with Ubuntu Budgie -- Grub, kernel/initrd files in the /boot directory, but that is not helpful in understanding your situation because Ubuntu sets up very differently than Solus.